Ferrous alloy



tained.

Patented June 24, 1947 UNITED STATES PATENT OFFICE .FERROUS ALLOY Inc., Canton, Ohio No Drawing. Application February 9, 1945, Serial No. 577,146

2 Claims. 1

This invention relates generally to ferrous alloys, but has reference more particularly to alloys which are especially adapted for use in the form of castings, but which can also be used for hard facing purposes.

In our U. S. Patent No. 2,208,117, there is described a high-carbon ferrous alloy, containing substantial amounts of chromium, molybdenum. and nickel, such alloy being particularly useful for hard facing applications, requiring resistance to abrasion,

We have discovered that byadding silicon to the aforesaid alloy in amounts of from about 1% to about 3%, and by limiting the nickel content of such alloy to not more than 1.75%, we are able to increase the abrasion resistance of the alloy to a marked degree, and to maintain an as-cast hardness, in a A inch tool bit, for example, of over 66 Rock-Well C. If the nickel is increased to an amount appreciably in excess of 1.75%, such extreme hardness cannot be main- We have, for example, cast sand blast nozzles with our improved alloy, and have obtained a useful life, in such nozzles, about twice that of nozzles made with our aforesaid patented alloy.

The improved alloy contains from about 3.75% to 4.6% carbon, from about 8% to about 28% chromium, from about 6% to about 12% molybdenum, from about 1% to about 3% silicon, and nickel in appreciable amounts up to about 1.75%, the balance of the alloy being substantially all iron. An alloy within this range which has been found particularly useful in such applications as the casting of sand blast nozzles, contains about 4.3% carbon, about 16% chromium, about 2 8% molybdenum, about 2% silicon, and about 1% nickel, the balance of the alloy being substantially all iron.

The alloy is further characterized by the fact that it is strong and has a microstructure which contains a wealth of carbides in a hard ferritic matrix, In this, it is distinguished from the alloy disclosed in our U. S. Patent No. 2,208,117, in which the microstructure is primarily austenitic.

While the usefulness of the alloy for castings has been emphasized, it is to be understood that the alloy may also be utilized for hard facing purposes.

Having thus described our invention, we claim:

1. A ferrous alloy containing from about 3.75% to about 4.6% carbon, from about 8% to about 28% chromium, from about 6% to about 12% molybdenum, from about 1% to about 3% silicon, and nickel in appreciable amounts up to about 1.75%, the balance of the alloy being substantially all iron.

2. A ferrous alloy containing about 4.3% carbon, about 16% chromium, about 8% molybdenum, about 2% silicon, and about 1% nickel, the balance of the alloy being substantially all iron.

ARTHUR T. CAPE. CHARLES V. FOERSTER.

REFERENCES CITED The following references are of record in the file of this patent:

UN ITED STATES PATENTS Number Name Date 2,208,117 Cape July 16, 1940 2,208,116 Cape July 16, 1940 

